Lingual tube



FIG. 1 is a top front perspective view of a lingual tube according to the claimed design;

FIG. 2 is a bottom back perspective view of the lingual tube of FIG. 1;

FIG. 3 is a front elevation view of the lingual tube of FIG. 1;

FIG. 4 is a back elevation view of the lingual tube of FIG. 1;

FIG. 5 is a right side elevation view of the lingual tube of FIG. 1, the left side being identical thereto;

FIG. 6 is a top plan view of the lingual tube of FIG. 1; and,

FIG. 7 is a bottom plan view of the lingual tube of FIG. 1.

The broken lines in the figures are for the purposes of illustrating portions of the lingual tube or environmental structure that form no part of the claimed design. 

CLAIM The ornamental design for a lingual tube, as shown and described. 